On Fri, May 12, 2023 at 1:34 PM Florian Weimer <fweimer@redhat.com> wrote:
* Owen Taylor:

> On Wed, May 10, 2023 at 9:48 AM Florian Weimer <fweimer@redhat.com> wrote:
>
>  * Aoife Moloney:
>
>  > There are two types of Flatpak containers -
>  > runtimes - which contain unmodified Fedora packages,
>  > and applications - which contain Fedora packages rebuilt to relocate
>  > them from /usr to /app.
>
>  Is this relocation still required?
>
> Yes - the /app vs. /usr split is pretty fundamental to the operation
> of Flatpak, and this Change doesn't propose any changes to how Flatpak
> works, just how Flatpaks are built in Fedora.

Do you have a pointer where I can read up on the current approach?

Some references that I found quickly:

https://docs.fedoraproject.org/en-US/flatpak/concepts/
https://docs.flatpak.org/en/latest/basic-concepts.html

But neither goes into a lot of detail to motivation. I'm certainly willing to describe things in more detail or look around further if you still have questions.
 
I'm concerned that this is just like Software Collections with a
different path, which I believe where previously banned in Fedora (and
are generally a huge hassle on the releng side, I think).

The big distinction here is that there is no idea that these RPMs will be installed directly on a Fedora system. They are used only when building Flatpak containers. So I don't think there is much similarity to SCL's other than "built with a different prefix".

- Owen